Skip directly to site content Skip directly to page options Skip directly to A-Z link


Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People
														Search

		Submit


Tuberculosis (TB)


Facebook
        Twitter
        LinkedIn
        Syndicate





Guide to the Application of Genotyping to Tuberculosis Prevention and Control										Related Pages
										**Tuberculosis Genotyping Case Studies: How TB Programs Have Used Genotyping**
**Genotyping Used to Improve Contact and Cluster Investigations**
The Massachusetts Department of Public Health recently reported on their universal genotyping program and provided evidence that genotyping strengthened both their contact and cluster investigations (Miller 2002).
**Table 2.1.**Relationship or location of presumed transmission for 25 patients with suspected epidemiologic links detected during contact investigations that were not confirmed by subsequent genotyping results — Massachusetts, 1996–2000.
**Suspected relationship/ location of transmission**
**Number of misleading epidemiologic links**Homeless shelter
11Household members
5Workplace
4Friends/social contacts
3Non-household family members
2**Total**
**25**From 1996 through 2000, Massachusetts used routine contact investigations to identify 92 epidemiologic links between 984 persons with TB. Subsequent genotyping results with IS*6110*-based RFLP and spoligotyping confirmed that 67 (73%) of these had matching genotype patterns. In 25 (27%), however, the reported epidemiologic links were not supported by matching genotyping results. The reported relationships or locations of transmission that were revealed by genotyping to be misleading are shown in Table 2.1. In addition to identifying misleading epidemiologic links, the Massachusetts program used universal genotyping and subsequent cluster investigations to identify 21 patients who shared genotyping matches and epidemiologic links that were not found by routine contact investigations (Table 2.2). The settings of transmission for these unexpected epidemiologic links were often nontraditional, and at least one cluster consisting of three patients was the result of casual transmission. The routine contact investigations found nothing in common among the three, but the subsequent cluster investigation established that one patient had been the hairdresser of the second patient, who spent time in a college dormitory where the third patient was a security guard.
**Table 2.2.** Newly recognized transmission settings detected by cluster investigations, Massachusetts.
**Newly recognized transmission setting**
**Number of TB patients with newly discovered epidemiologic links**Hair salon, college building
3Bar
2Public housing
2Prison
2Long-term care facility
2Fast food restaurant
2Buddhist temple
2Community barbecue
2Neighborhood market
2Neighborhood
2**Total**
**21**“Universal genotyping has proved to be an invaluable tool for the Massachusetts TB Division. Data provided through this mechanism has driven our strategic planning process. Not only can we better understand transmission trends in our state, we can also identify cross contamination more quickly as well as prove (or disprove) cases that appear to be related. It is also a key core element of our Outbreak/ High Profile Incident Response Plan and we have used it as a tool for recent outbreaks among the homeless, and a cluster of Somalian cases. It is hard to imagine now, a TB Program without genotyping.”
Sue Etkind, RN, MS
Director
TB Prevention and Control
Massachusetts Department of Public Health
							
					
						Page last reviewed:  September 1, 2012					Content source: 	Division of Tuberculosis Elimination, National Center for HIV, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention homeGuide to the Application of Genotyping to Tuberculosis Prevention and Control
Acknowledgments
Introduction to Tuberculosis Genotypingplus icon
Introduction to this Guide
Overview of Tuberculosis Genotyping
Overview of the CDC Tuberculosis Genotyping Program
TB Program Eligibility and Application Procedures
Tuberculosis Genotyping Case Studiesplus icon
Investigation of a Genotyping Cluster in a Low-Incidence State
Apparent Genotyping Cluster among Recent Immigrants from the Philippines
False-Positive Culture Investigation
Algorithm to Detect False-Positive Cultures
A Misdiagnosis that was Identified with Genotyping
Genotyping Used to Improve Contact and Cluster Investigations
Identification of Nontraditional Transmission Settings
Investigation of a Multistate Tuberculosis Outbreak
Homeless Shelter Outbreak Investigation
Using Genotyping to Evaluate the Impact of a Screening Program
CDC Tuberculosis Genotyping Laboratory Proceduresplus icon
Science behind Tuberculosis Genotyping
Description of Genotyping Methods
Submission of Isolates
Genotyping Results, Designation of Clusters, and Reporting
Suspected False-Positive Cultures
IS*6110*-based RFLP Analysis
Combining Genotyping and Epidemiologic Data to Improve Our Understanding of TB Transmissionplus icon
Definitions
Reading the Genotyping Laboratory Report
Comparing Genotyping and Epidemiologic Results from Two TB Patients
Comparing Genotyping and Epidemiologic Results from Three or More TB Patients
Clustering as a Surrogate Measure of Recent Transmission
Developing a Tuberculosis Genotyping Programplus icon
Developing a Written Plan
Initial Decisions
Establishing Procedures for:plus icon
Submitting Isolates
Receiving and Acting on Genotyping Results
Requesting RFLP Analysis
Submitting Additional Isolates from the Same Patient
Comparing Genotyping Results between Jurisdictions
False-Positive Cultures
Database Management and Quality Control
Special Issues
Applying Genotyping Results to Tuberculosis Control Practicesplus icon
Evaluating Matching Genotypes
Evaluating Nonmatching Genotypes
Suspected False-Positive Culture Investigations
Expanded Contact Investigations
Outbreak Investigations
Cluster Investigations
Monitoring Trends
Appendicesplus icon
Appendix A: Glossary and Abbreviations
Appendix B: References and Useful Resourcesplus icon
References Cited in the Guide
NTGSN Special Issue References
Information on Packaging and Shipping Infectious Substances
Core Steps of an Outbreak Investigation
Consultants Available to Offer Guidance To receive email updates about this page, enter your email address: Email Address			What's this?				Submit


About CDC
					Contact Us
					800-232-4636
 Facebook Twitter Instagram LinkedIn Youtube Pinterest Snapchat
 CONTACT CDC
				Contact Us
							Call 800-232-4636
							Email Us
			ABOUT CDC
				About CDC
							Jobs
							Funding
			POLICIES
				Accessibility
							External Links
							Privacy
							Policies
							No Fear Act
							FOIA
							OIG
							Nondiscrimination
							Vulnerability Disclosure Policy
			CONNECT WITH US
				Facebook
								Twitter
								Instagram
								LinkedIn
							Youtube
								Pinterest
								Snapchat
								Email
			LANGUAGES
				Español
							繁體中文
							Tiếng Việt
							한국어
							Tagalog
							Русский
							العربية
							Kreyòl Ayisyen
							Français
							Polski
							Português
							Italiano
							Deutsch
							日本語
							فارسی
							English


U.S. Department of Health & Human Services
			Accessibility
			External Links
			Privacy
			Policies
			No Fear Act
			FOIA
			Nondiscrimination
			OIG
			Vulnerability Disclosure Policy
			USA.gov


Exit Notification / Disclaimer Policy Close
 Links with this icon  indicate that you are leaving the CDC website. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
				Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
				You will be subject to the destination website's privacy policy when you follow the link.
				CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. Website Disclaimers
 Cancel Continue